HELP! New to routers etc. mine not working

I have a Linksys wireless-G 2.4 GHz 802.11g with speed booster. I have all my other computers hooked up with the USB linksys network adapters, same 2.4 GHz etc. My signal comes from hughsnet satelite the cable goes in the router and the signal to the USB adapters.
It was working fine now it wont get any of the other computers online, it shows a great signal strength, but no internet. I here about trying to change channels, but have no clue how. I here about upgrading firmware but have no clue which one goes with my stuff, or if it will help, or if it might help me access parts of the setup easier. but wouldnt know what i was looking at anyway.
I will start there and see If someone can give me a starting place.